Refrigerating system



Jan. 21, 1936. F. B. HUNT A REFRIGERATING SYSTEM Filed April 24, 1951 Patented Jan. 2.11, 1936` UNITED STATES PATENT OFFICE BEFBIGERATNG SYSTEM Franklin B. Hunt, Chicago, 111.', assignor to The Liquid Carbonic Corporation, Chicago. IIL, a corporation of Delaware A Application April 24, 1931, serial No. 532,439

1s claims. (c1. isz- 115) The object of the present invention is to provide a refrigerat-lng system particularly adapted for use where it is desired to maintain substantially aA given temperature in one chamber vand to maintain a materially lower temperature in another chamber, utilizing one compressor only in the system. 'I'he primary object of the invention is to provide a system of the character indicated in which the demands upon the refrigerat-` ing unit located in the first-mentioned chamber will necessarily be completely satisfied before any refrigerant is delivered to the unit in control of the second chamber. Further objects of the invention will appear as the description proceeds.

' embodiment of my invention; and

Fig. 2 is ya diagrammatic representation of another embodiment of my invention.

The herein disclosed system is admirably adapted for Vsoda fountain use, and l have illustrated a system specially designed for that use. It is to be understood, however, that the application of the system is not limited to soda fountains, but may be used elsewhere, and thatit is not limited to any particular refrigerant, though it will be described as adjusted for use with sulphur dioxide.

Referring more particularly to Fig. '1, it will be seen that I have illustrated a compressor I driv- I en by a motor II and adapted to supply compressed refrigerant through a cooling coil I2 to a condenser I3. The condenser I3 is -connected by a pipe I4 to a refrigerating unit I5 running through the syrup enclosure `and connected to one end I6 of a coil I1 located in the attemperating chamber for cooling soda and plain water. An automatic expansion `valve I8 set,'for instance, for a pressure of three and one-half pounds per square inch above atmospheric pressure is interposed in the line I4 in advance of the unit l5.

The opposite end I9 of the coil I1 is connected by a pipe 29 to an inlet port 2| located in the top of a. trap 22.

The trap 22 comprises a casing providing a chamber 23 having an outlet 24 through its top, and having a second outlet 25 through its bottom. A float 23 is positioned within the chamber 23 and may be provided with an arm 21` formed adjacent its upper end with an elongated slot 26. The slot 28 operatively4 receives-a .pin 29 carried by` an arm 30 pivoted' at 3l on a sleeve 32 carried 5 by a conduit 34 communicating with the port 24.

A valve 33 is carried by the arm 30 and controls flow through the conduit 34.

A pipe 35 connects the port 24 with a pipe 36 leading to the intake of the compressor I0, and preferably opening into the crank case of said compressor.

A pipe 731 connects the port 25 with onefend 38 of` a second refrgerating coil 39 located in a brine chamber for cooling ice cream; A second expansion valve 40, 'set for about ten pounds per square inch pressure absolute is interposed in the line 31 between the trap 22 and the coil 39. The opposite end 4I of the coil 39 is connected by the pipe 42 to the pipe 36. '20

A switch 44, controlled by a thermo-responsive nement as disposed within the innuence or the coil 39 Vcontrols current flow from the line 49 through the connections 41 to the motor I I.

If the whole installation is warm, liquid refrigerant will forceV its way through the line I4 past the valve I8 through the-unit I5 and into they coil I1. At first, all of the refrigerant will be vaporized in the unit I5 and in the coil I1. so that only gaseous refrigerant will reach the trap 3o 22.' So long as there is no liquid in the trap 22, the weight of the noat 26 will hold the valve 33 open and, with the compressor operating, all of such gaseous refrigerant will now through the port 24 and the pipes 35 and 36 back to the com- 35 pressor Ill, no refrigerant 'being supplied to the coil 39.

Assuming that the units I5 and I1 are, in accordance with usual practice, submerged in water, ice will begin to form on those units. As this ice 40 gets thicker and thicker, less and less of the refrigerant will be vaporized in these units, and

liquid refrigerant will be fed into the trap 22. As the liquid level in the -trap 22 builds up, the float 26 is elevated to move the valve 33 into position 45 to close the port 24. Flow of gas through the lines and 36 is thus stopped, and iiow of liquid to the coil 'I1 isy likewise stopped. The compressor, however, continues to operate and reduce the pressure in coil 39 so as to allow flow ofthe liquid 50 from the trap 22 through the' port 25 and line 31 and past the expansion valve 40, where the pressure is reduced to about ten pounds per square inch absolute. 'I'he refrigerant flows thence to the coil 39 to refrigerate the brine in which said 55V coil is submerged, and such refrigeration will continue as long as liquid flow from the trap 22 continues.

However, as soon as the liquid in the trap 22 has 5 been exhausted sufliciently to permit the oat 26 to drop, the valve 33 is opened and, because of the high pressure for which the valve I8 is set, the pressure in the coil 39 through the pipe 35 and pipe 42 closes the valve 40, so that no work will be done in the coil 39 until the valve 33 is again closed.

This shifting of iiow from the coil l1 to the coil 39 continues until the brine around the coil 39 reaches a temperature at. which the thermostat- A ically operated switch 44 opens the motor circuit and stops the compressor.

It will vbe obvious that the compressor will continue to operate until suiiicient liquid 'has vaporized in the coil 39 to bring the brine to the desired temperature. If the load on the coil Il lincreases, as it does in practice, practically all of the liquid may vaporize in that-coil, and very vlittle, if any liquid will be fed to the coil 39until the demands of this new load condition on the coil l1 have been satisfied.

Whenever the valve 33 is open, the crank case pressure of the compressor will rise to correspond to the setting of the valve I 8. Thus, the high temperature load will be carried -with a correspondygg-ingly high back pressure, giving high capacity and efliciency. 'I'he low temperature load, on the other hand, will be carried at a lower back pressure, but the liquid which reaches the expansion valve 40 has already passed through the valve I8 so that the flash gas which is evolved in cooling the liquid to the temperature impressed upon the coil- I1 will go back tothe compressor when the port 24 is open, at'the high back pressure.

A refrigerant which carries oil with it will function in this system, as the oil is trapped in the trap 22, but will be discharged through the valve 4I) and the coil 39, and returned to the crank case. This carrying of oil can not stop the compressor, since the oil, in passing through the coil 39, does not do any refrigerating work, and the machine must continue to operate until the thermostat is satisfied.

Referring, now, to Fig. 2, it will be seen that I have illustrated a similar system so arranged as to obtain a multi-compressioneifect. The compressor is provided with a crank shaft 5I within its crank case, said crank shaft being driven by a motor 82. A piston 52 connects a piston 53 to said crank shaft 5I, the piston 53 being mounted for reciprocation in the cylinder 83 of the machine. The piston 53 is formed with a longitudinal bore 54 therethrough providing communicationv between the crank case and the cylinder, a check valve 55 being provided to enforce unidirectional ow through said bore 54 from the crank case to the cylinder.

Compressed refrigerant is supplied through a cooling coil 56 to a condenser 51, and thence by a pipe 58 through a refrigerating unit 59 con- 5-.nected to one end 60 of a coil 6|, an expansion valve 62 being interposed in the line. The oppovsite end 63 of the coil 6| is connected by a pipe 64 to inlet port 66 of a trap 65v corresponding to the trap 22 and provided with a valved outlet f port 61'and with a secondoutlet port '68. A line 69 is connected to the port 61, and delivers, at

10, into the cylinder 83 at a point just above the lower limit of the stroke of the piston 53. As is '75 clearly illustrated, the port 10 is closed by the piston at all times except when said piston is at the lower limit of its stroke.

A pipe 1I connects the port 68 with one end 12 of a second refrigerating coil 13, an expansion valve 14 being interposed in that line. The opposite end 15 of the coil 13 is connected by a pipe 16 with the crank case of the compressor 58. A thermostatic element 18 disposed' within the influence of the coil 13 controls a ,switch 19 which in turn, controls the flow of current from a supply line 8|) through the connections 8l to the motor 82.

The operation of the embodiment illustrated in Fig. 2 is substantially identical with the oper.- ation of the embodiment illustrated'in Fig. 1, except that the high pressure returning gas flowing from the port 61 is injected directly into the cylinder of the compressor to `increase the mass of gas therein just before the initiation of the up stroke of the piston 53.

I claim as my invention:

1. In a refrigerating system, a source of volatile liquid refrigerant, a refrigerating element connected to said source, a second refrigerating element connected to said source through said first refrigerating element, and automatic means for preventing flow of refrigerant to said second refrigerating element at all times when the demands upon said rst refrigerating element are not satisfied.

2. In a refrigerating system, a source of volatile liquid refrigerant, 'a refrigerating element connected to said source, a second refrigerating element connected to s aid source through said rst refrigerating element, valve means interposed between said refrigerating elements and normally preventing ilow of refrigerant to said second re- ,frigerating element, and means associated with said valve means, and actuable only by liquid refrigerant discharged from said rstrefrigerating element and unresponsive to. variation in pressure difference between said refrigerating elements to shift said valve means to permit ow of refrigerant to said second refrigerating element.

3. The combination with a compressor for volatile fluid and a condenser therefor, of a hightemperature cooling unit connected to said condenser 4and supplied therefrom, atrap having an inlet, a gas outlet, and a liquid outlet, means connecting said unit to said trap inlet, a low-temperature cooling unit, means connecting said lowtemperature unit to said trap liquid outlet, a valve controlling said gas outlet, a conduit connecting said gas outlet tothe intake of said compressor, and a conduit connecting said low-temperature unit to the intake of said compressor.

4. 'I'he combination with a compressor for volatile uid and a condensern therefor, of a hightemperature cooling unit connected to said condenser and supplied therefrom, a trap having an inlet, a gas outlet, and a liquid outlet, means connecting said unit to said trap inlet, a lowtemperature cooling unit, means connecting said low-temperature unit to said trap liquid outlet, a valve controlling said gas outlet, a oat in said trap and operatively connected to said trap valve, a conduit connecting said gas outletto the intake of said compressor, and a conduit connect-V denser and supplied therefrom, an expansion valve interposed between said condenser and said unit. a trap having an inlet, a gas outletand a liquid outlet, means connecting said .unit to said trap inlet, a low-temperature cooling unit, means connecting said low-temperature unit to said trap liquid outlet, an expansion valve interposed in said last-named connecting means, a valve controlling said gas outlet, a conduit connecting said gas outlet to the intake of said compressor,l and a conduit connecting said low-temperature unit to the intake of said compressor.

6. The combination with a compressor for volatile iiuid and a condenser therefor, of a hightemperature cooling unit connected to said condenser and supplied therefrom, an expansion valve interposed between said condenser and said unit, a trap having an inlet, a gas outlet, and a liquid outlet, means connectingl said unit to .said trap inlet, a low-temperature cooling unit,

means connecting said low-temperature unit to said trap liquid outlet, an expansion valve interposed in said last-named'connecting means and set to open at a pressure lower than the pressure required to open said first-named expansion valve, a valve controlling said gas outlet, a conduit connecting said gas outlet to the intake of said compressor, and a conduit connecting said low-temperature unit to the intake of said compressor.

'1. The combination with a compressor for volatile uid and a condenser therefor, of a high-temperature cooling unit connected to said condenser and supplied therefrom, `a trap having an inlet, a gas outlet, and a liquid outlet, means connecting said unit to said trap inlet, a low-temperature cooling unit, means connecting said low-temperature unit to said trap liquid outlet, a valve controlling said gas outlet, a float in said trap and operatively connected to close said trap valve upon a rise of liquid in said trap, a conduit connecting said gas outlet to theintake of said compressor, and a conduit connecting said low-temperature unit to the intake of said compressor.

8. The combination with a compressor for volatile. uid Vand a condenser therefor, of a hightemperature cooling unit connected to said condenser and supplied therefrom, an expansion `valve interposed between said condenser and said unit, a trap having an inlet, a gas outlet, andl a liquid outlet, means connecting said unit to said trap inlet, a low-temperature cooling unit, means connecting said low-temperature u nit to said trap vliquid outlet, a second expansion valve interposed in said last-named connecting means and set to open at a pressure lower than the pressure required to open said first-named expansion valve,d a valve controlling said gas outlet, a iioat in said trap and operatively connected to said trap valve, said float being operable, upon collection of liquid refrigerant in said trap delivered through said high-temperature unit, to close said trap valve, a conduit connecting said gas outlet to the intake of said compressor, and a conduit connecting said low-temperature unit to the intake of 'said compressor. f g

9. In combination, a compressor comprising a crank case, a cylinder, a crankshaft in said case,

' a piston operatively connected to said crank shaft and reciprocable in said cylinder, said piston being formed with a longitudinal bore, a check valve associated with said bore and enforcing'unidirectional ow therethrough from said crank case to said cylinder, means for driving said crank shaft,

a condenser connected to the outlet of said coml operable to close said valve upon upward movepressor, a high-temperature cooling unit having its one end connected to said condenser, a casing connected to the other end of s`aid imit, said casing having a plurality of outlets, valve means controlling the course of iiuid ow from said casing, means connecting one of said outlets to said cylinder at a point spaced outwardly beyond the inner limit of the stroke oi said piston, means connecting another of said outlets to one end of a. low-temperature cooling unit, and means connecting the other end of said last-named unit to said crank case.

10..A refrigerating system comprising a compressor, a motor for driving said compressor,v a l refrigerating unit having its one end connected to the outlet of said compressor., a second refrigerating unit having its one end connected to the other end of said ilrst refrigerating unit, and having its other end connected to the intake of said compressor, means interposed between said refrigerating units and operative to prevent fluid flow to said second refrigerating-unit until the demands upon said first-mentioned refrigerating unit have been satisfied, means cooperating with said last-mentioned means for connecting the last-mentioned end of said first-mentioned refrigerating unit to the intake of said compressor, and temperature-responsive means disposed within the inuence of said second refrigerating unit for controlling operation of said motor.

11. In combination, a compressor for a volatile refrigerating fluid, a condenser connected to the. outlet of said compressor, a motor for driving said compressor, a refrigerating coil having one end connected to said condenser to receive liquid refrigerant therefrom, an expansion valve interposed between said condenser and said coil, a trap having an inlet port and an outlet port adjacent its upper end and having an outlet port adjacent its lower end, a conduit connecting the other end of said coil to said trap inle't port, a valve for controlling said upper outlet port, a oat in said trap in control of said valve and operable to close said valve upon upward movement of said iioat, 4a conduit connecting said valved port to the intake of said compressor, a second refrigerating coil, a conduit connecting said lower outlet port to one end of said second coil, an ex-l pansion valve in said conduit, and a conduit connecting the other end of said second coil to l50 said compressor intake.

12. In combination, va compressor for a voltatile refrigerating fluid, a condenser connected to the outlet of said compressor, a motor for driving ing said compressor, a refrigerating coil having one end connected to said condenser to receive liquid refrigerant therefrom, an expansion valve interposed between said condenser and said coil, a trap having an inlet port and an outlet port adjacent its upper end and having an outlet port adjacent its lower end, a conduit connecting the other end o'f said coil to said trap inlet port, a valve' for controlling said upper outlet port, a oat in said trap in control of said valve and ment of said oat', -a conduit connecting said valved port to the. intake of said compressor, a second refrigerating coil, a conduit connecting said lower outlet port to one end of said second coil, an expansion valve in said conduit, a conduit connecting the other end of said second coil. to said compressor intake, and temperature-y l responsive means disposed within the influence of said second coil for controlling said motor.

V13. In combination, a compressor fora volatile 7l refrigerating fiuid, a condenser connected to the outlet of said compressor, a. motor for driving' of said coil to said trap inlet` port, a valve ,for

controlling said upper outlet port, a float in said trap in control of said valve and operable to close said valve upon upward movement of said float, a conduit connecting said valved port to the intake of said compressor, a second refrigerating coil, a conduit connecting said lower outlet port to one end of said second coil, an expansion valve said conduit and set for a pressure lower than that for which said first-mentioned expansion valve is set, and a conduit connecting the other end of said second coil to said compressor intake.

14. In combination, a compressor comprising a crank case, a cylinder, a crank shaft in said case, a piston operatively connected to said crank shaft and reciprocable in said cylinder, said piston being formed with a longitudinal bore, a check valve associated with saidbore and enforcing unidirectional flow therethrough from said crank case to said cylinder, a motor connected to drive said crank shaft, a condenser connected to the outlet of said compressor, a refrigerating coil having one ,end connected to said condenser to reoeive liquid refrigerant therefrom, an expansion valve interposed between said condenser and said coil, a trap having an inlet port and an outlet port adjacent its upper end and having an outlet port adjacent its lower end, a conduit connecting the other end of said coil to said trap inlet port, a, valve for controlling said upper outlet port, a float in said trap in control of(v said valve and operable to close said valveupon upward movement of said oat,. a conduit connecting said valved port to said cylinder at a point spaced outwardly beyond the inner limit of the stroke of said piston, a second refrigerating coil, a conduit connecting said lower outlet port to one end of said second refrigerating coil, an expansion valve in said conduit, and a conduit connecting thev other end of said second coil to said crank oase.

15. In a refrigerating system, a source of volatile liquid refrigerant, a first refrigerating element, a second refrigerating element, means connecting said refrigerating elements in series with said source, and means interposed between said refrigerating eiements and operable to direct flow from said first refrigerating element to said second refrigerating element only after the demands upon said first refrigerating element have been satisfied.

16. In a refrigerating system, a source of volatile liquid refrigerant, a refrigerating element connected to said source, -a second refrigerating element connected to said source through said first refrigerating element, and a diverter valve interposed `between said refrigerating elements and operable to direct ow from said first refrigerating element to said source until the demands upon said first refrigerating element have been satisfied, and thereafter to direct flow from said first refrigerating element to said second refrigerating element until the demands upon said first refrigerating element exceed the capacity of the refrigerant supplied thereto.

17. In a. refrigerating system, a compressor for volatile liquid, a condenser connected to the discharge port of said compressor, a refrigerating element connected to be supplied with liquid refrigerant from said condenser, a. second refrigerating element, a chamber having an inlet port, an upper outlet port, and a lower outlet port, means connecting said first refrigerating element with said inlet port, means connecting said upper outlet -port with the intake port of said compressor, means connecting said lower outlet port with said refrigerating element, a. valve controlling said upper outlet port, and oat means movable upwardly to close said valve.

18. In a refrigerating system, a compressor for volatile liquid, a condenser connected to the dis= charge port of said compressor, a refrigerating element connected to be supplied with' iiquid refrigerant from said condenser, a second refrigerating element', a chamber having an inlet port, an upper outlet port, and a lower outlet port, means connecting said first refrigerating element with said inlet port, means connecting said upper out-'- let port with the intake port of said compressor, means connecting said lower outlet port with said second refrigerating element, a valve controlling one of said outlet ports, and oat means completely dominating said valve and operable, only under the influence of liquid refrigerant supplied to said chamber, to shift said valve to permit flow of refrigerant to said second refrigerating element.

FRANKLIN B. HUNT. 

